Three-dimensional video image pick-up and display system using a reference window and standard stereoscopic video data

ABSTRACT

A virtual field-of-view frame or reference window in a field of view of a stereo camera, and projected in a reduced manner by left and right shooting lenses to form an image on each of a left and right image pickup devices. Standard image data and stereoscopic video data is sent. The standard stereoscopic video data is displayed on a display screen having positions of left and right screens exactly matching each other and having the position and size for reproducing and displaying the reference window as a reference dimension display equivalent to the reference window, simultaneously with left and right polarizations. With eyeglasses for field-of-view separation left and right videos are separately viewed.

TECHNICAL FIELD

The present invention relates to imaging and displaying of stereoscopicvideo (moving pictures and still pictures) in two-eye stereoscopy modein which video shot by two, left and right lenses is viewed by each ofthe left and right eyes, pushing ahead with making video (image)stereoscopic in the field of transmission and reception of images usingtelevision broadcasting and communication lines and other fields, byutilizing the same video data even with different display screen sizesor different models of displaying apparatus.

BACKGROUND ART

Conventionally, electronic stereoscopic video imaging display systems intwo-eye stereoscopy mode have been suggested, exhibited, and put onsale. Also, stereoscopic television broadcasting has already started insome places.

In these conventional electronic stereoscopic video imaging displaysystems, in order to use different systems for each model in a mixedmanner, adjustment is required on a display side by shifting an image orthe like. However, the adjusting method in these conventional methods isimperfect, and its general implementation is difficult.

(For example, refer to Patent Document 1).

-   Patent Document Japanese Unexamined Patent Application Publication    No. 8-275207

DISCLOSURE OF INVENTION Problem to be Solved by the Invention

Thus, in order to allow stereoscopic video to be reproduced on a displayside without adjustment even with different models of stereoscopic videodisplaying apparatus, a technological problem to be solved occurs, andan object of the present invention is to solve this problem.

Means to Solve the Problem

The present invention is suggested to attain the object described above.In the invention described in an embodiment, a stereoscopic videoimaging display system reproducing the state of stereoscopy with highfidelity is provided. A virtual field-of-view frame (defined as areference window) is set in a field of view of a stereo cameraconfigured of paired imaging units each configured of a shooting lensand an imaging pickup device placed on left and right in parallel toeach other, and the reference window is projected in a reduced manner bythe left and right shooting lenses to form an image on each of the leftand right image pickup devices. Image data of an image of the referencewindow (in the window) formed on the left and right image pickup devicesis read, and stereoscopic video data (defined as standard stereoscopicvideo data) is sent. On a display side, the standard stereoscopic videodata is displayed with an electronic display on a display screen (ascreen having the positions of left and right screens exactly matchingeach other and having the position and size for reproducing anddisplaying the reference window in full size is defined as a referencedimension display screen) equivalent to the reference window,simultaneously with left and right polarizations orthogonal to eachother or circular polarizations in counterclockwise and clockwisedirections or alternately with linear polarization in a same directionin a time-division manner. With eyeglasses for field-of-view separationcorresponding to the polarizing scheme, left and right videos areseparately viewed.

According to this configuration, by setting a reference window at thetime of shooting, sending standard stereoscopic video data in a windowprojected to each of the left and right image pickup devices, and takinga screen in the case of enlarging and displaying it on a display sidewith the same size as the reference window as a reference dimensiondisplay screen of stereoscopic video display, shot image is reproducedwith high fidelity.

In the invention described in another embodiment, a stereo camera isprovided, in which a reference window, which is a virtual field-of-viewframe, is set in a field of view of a stereo camera configured of twoimaging units each configured of a shooting lens and an imaging pickupdevice placed on left and right in parallel to each other, image data inan image of each of the left and right reference windows projected in areduced manner on each of the left and right image pickup devices isread, and standard stereoscopic video data is sent.

According to this configuration, by setting a reference window in thestereo camera, the sent image data is made to scale, and is send asstandard stereoscopic video data. Thus, even when the stereo camera issingly used, the distance and size of the shot image can be accuratelyreproduced in a device on a reproducing side, the shot data can becommonly shared as standard stereoscopic video data irrespectively ofthe type and size of device.

In the invention described in another embodiment, an apparatus on adisplay side of a system in which a reference window, which is a virtualfield-of-view frame, is set in a field of view of a stereo cameraconfigured of two imaging units each configured of a shooting lens andan imaging pickup device placed on left and right in parallel to eachother, image data in an image of each of the left and right referencewindows projected in a reduced manner on each of the left and rightimage pickup devices is read and sent as standard stereoscopic videodata, and stereoscopic video is displayed based on the standardstereoscopic video data. Display is made (simultaneously with left andright polarizations orthogonal to each other or circular polarizationsin counterclockwise and clockwise directions or alternately with leftand right polarizations in the same direction in a time-division manner)at same left and right arbitrary positions in an entire width of leftand right fields of view within a left view angle determined by linesconnecting both ends of the reference dimension display screen and aleft eye of an observer and a right view angle determined by linesconnecting both the ends of the reference dimension display screen and aright eye thereof. With this, stereoscopic video is reproduced with highfidelity.

According to this configuration, even when the actual display size ofthe stereoscopic video displaying apparatus is larger than the referencewindow (display screen in reference dimensions) set in the imagingapparatus, furthermore, is in an overlap display range in which left andright videos overlap each other, or is a horizontal side-by-side displayrange in which left and right videos are placed side by side, it isenough to only display stereoscopic video data with a defined displaywidth (depicted in FIG. 1) with respect to the display position (viewdistance).

In the invention described in another embodiment, a system using digitalTV broadcasting waves as data conveying means from the stereoscopicvideo imaging apparatus for obtaining the standard stereoscopic videodata to a stereo video displaying apparatus is provided.

According to this configuration, since the stereoscopic video data isstandardized, stereoscopic television broadcasting can be achieved withthe conventional system without requiring any special contrivance. Inparticular, digital TV broadcasting is transmitted as being divided intoslots, has a margin of carrier waves even in the case of high-definitiontelevision, and is thus suitable for synchronizing two left and rightvideo signals with each other for transmission.

In the invention described in another embodiment, a system using acommunication line as data conveying means from the stereoscopic videoimaging apparatus for obtaining stereoscopic video to a stereoscopicvideo display apparatus.

According to this configuration, since the stereoscopic video data isstandardized, stereoscopic video can be freely transmitted and receivedover the Internet through a high-speed communication line (opticalfiber).

In the invention described in another embodiment, a stereoscopic videodisplaying apparatus is provided, which is a stereo projector in whichpaired left and right projection units are placed side by side, and leftand right linear polarizing filters in a direction in which they areorthogonal to each other or left and right circular-polarizing filterswith rotating directions being opposite directions are mounted on theleft and right units, respectively. A distance between optical axes ofleft and right projection lenses is set at a human interpupillarydistance. And, left and right electronic displays are symmetricallyoffset or a display range is set offset so that left and rightprojection screens match each other (at a position) on a referencedimension display screen. And, a projection distance is set longer thana view distance.

According to this configuration, only display on the left and rightelectronic displays based on the standard stereoscopic video data isrequired. Irrespectively of the size of screen to be projected, in theentire projection range (from a small screen size with a shortprojection distance to a large screen size with a long projectiondistance), only focusing adjustment is required. And, substantialoperations are similar to those for a mono projector.

Also, when the stereo projector is set at a position equivalent to theposition of the eyes of the observer, a problem occurs such that theprojector itself becomes an obstruction. This problem can be solved bysetting the view distance longer than the projection distance.

In the invention described in another embodiment, a stereoscopic videodisplaying apparatus is provided, which is a stereo projector in whichpaired left and right projection units are placed side by side, and leftand right linear polarizing filters in a direction in which they areorthogonal to each other or left and right circular-polarizing filterswith rotating directions being opposite directions are mounted on theleft and right units, respectively. A distance between optical axes ofleft and right projection lenses is set at a human interpupillarydistance. And, left and right electronic displays are symmetricallyoffset or a display range is set offset so that left and rightprojection screens match each other (at a position) on a referencedimension display screen. And, a projection distance is set shorter thana view distance.

According to this configuration, the size of a rear-projection-typestereoscopic video displaying apparatus (rear-projection-typestereoscopic TV) in a depth direction can be advantageously made small(thin).

In the invention described in an embodiment, a stereoscopic videodisplaying apparatus is provided in which, with one projection unitformed of an electronic display and a projection lens, left and rightimages of stereoscopic video are alternately displayed in atime-division manner on a screen based on standard stereoscopic video,and the apparatus has an infrared-ray sending apparatus forsynchronization placed therefor.

Also, when stereoscopic video is viewed with the stereoscopic videodisplaying apparatus of the embodiment described above, liquid-crystalshutter eyeglasses, which is of a conventional type, may be synchronizedwith infrared rays. Furthermore, optimally, a polarizing filter ismounted on the projector described above for alternately displaying theleft and right videos of the stereoscopic video in a time-divisionmanner with polarization in the same direction, and the left and rightfields of view are separately viewed with “eyeglasses for stereoscopicvideo viewing.”

Description of the “eyeglasses for stereoscopic video viewing”: on theleft and right sides of eyeglasses for stereoscopic video viewing forseparately viewing left and right fields of view, left and rightpolarizing plate identical to each other are mounted, respectively.Furthermore, on its front surface, a liquid-crystal plate is mounted.Also, on the eyeglasses, a tilt-angle sensor is mounted. Light beamsalternately reflected by the stereoscopic video displaying apparatusonto a screen are polarized light beams in the same direction. When thepolarizing plates of the eyeglasses are set in a direction orthogonal toa direction of light-shielding of polarized light beams reflected fromthe screen, the left and right fields of view of the eyeglasses areclosed to become dark. The state of the fields of view is changed in amanner such that a polarizing direction of reflected light from thescreen is optically rotated by 90 degrees or 270 degrees by theliquid-crystal plate mounted on the front surface to cause both left andright fields of view to be in an open state and viewed brightly. When avoltage is alternately applied to the liquid-crystal plate mounted onthe front surface of the eyeglasses with infrared rays sent insynchronization with a display image on the screen, the liquid crystalbecomes in a tension state with that voltage. As for polarized lightreflected from the screen and entering the eyeglasses, the polarizingdirection is kept as it is, and light-shielding is made by thepolarizing plates of the eyeglasses, causing the fields of view to bedark. At the same time, when a voltage is alternately applied to theliquid-crystal plates of the eyeglasses with infrared rays insynchronization with displayed video on the screen, the left and rightfields of view are alternately opened and closed, and the left and rightfields of view for viewing the screen is separated, thereby allowingstereoscopy. Also, when the eyeglasses are tilted, a relativedirectional relation between the screen and the polarizing direction ofthe eyeglasses is distorted to cause crosstalk, but the crosstalk isprevented by controlling and correcting the voltage to be applied to theliquid-crystal plate with the tilt-angle sensor.

In the invention described in another embodiment, a stereoscopictelevision is provided, in which a linear-polarizing filter is mountedon a front surface or a rear surface of a projection lens of arear-projection-type TV having a reference dimension display screenusing a DMD projection unit, left and right video are displayed in atime-division manner and, at the same time of time-division display, asynchronizing signal is sent from an infrared-ray synchronizing signalsending apparatus for field-of-view separation mounted on the TV.

According to this configuration, implementation can be easily achievedonly by mounting a polarizing filter on a projection unit of theDMD-type rear-projection TV of a conventional type itself. Also, at thetime of viewing, the eyeglasses for stereoscopic video viewing are usedfor stereoscopy.

In the invention described in another embodiment, a stereoscopictelevision is provided, which is a rear-projection-type TV having areference dimension display screen using an LCOS unit, in which left andright videos are displayed in a time-division manner and, at the sametime of time-division display, a synchronizing signal is sent from aninfrared-ray synchronizing signal sending apparatus for field-of-viewseparation mounted on the TV.

According to this configuration, since light beams emitted from the LCOSdevice is polarized, a polarizing filter is not required to be mountedon the projection unit, which simplifies the television more than theDMD type above.

In the invention described in another embodiment, a liquid-crystal celland a λ/4 plated are further added to the TV (of a DMD rear projectortype) having the configuration described in an embodiment above.Linearly polarized light passing through a polarizing filter isalternately rotated in polarizing direction by the liquid-crystal cellso as to be incident at 45 degrees and −45 degrees with respect to afast axis of the λ/4 plate, thereby displaying left and right images ofstereoscopic video projected onto a transmission-type screen withcircular polarization with rotation in different directions.

According to this configuration, since light beams for displaying leftand right videos are circularly polarized with rotation in differentdirections, it is enough to use circular-polarization eyeglasses withopposite left and right glasses for viewing, and no infrared-raysynchronizing apparatus is required. Also, by using circularpolarization, no crosstalk occurs even the viewer tilts his or her head(eyeglasses). However, since the operation of the λ/4 plate isunbalanced with respect to waveform, a light-shielding state may beincomplete in some cases, depending on the color.

In the invention described in another embodiment, the DMD unit describedin an embodiment above is replaced by an LCOS unit.

According to this configuration, since light beams emitted from the LCOSdevice is polarized, a polarizing filter is not required to be mountedon the projection unit, which simplifies the television more than theDMD type above.

In the invention described in another embodiment, a stereoscopictelevision camera having a stereoscopic monitor is provided, and thestereoscopic monitor has an LCD disposed at a position near a distanceof distinct vision from an observer. On the LCD, left and right videosare alternately displayed in a time-division manner. The left image fordisplay is displayed with an entire width in left and right directionswithin a view angle determined by lines connecting both ends of areference dimension display screen and the left eye of an observer andthe right image for display is displayed with an entire width in leftand right directions within a view angle determined by lines connectingboth ends of the reference dimension display screen and the right eye ofthe observer. The observer mounts a polarizing plate immediately beforeeyeglasses mounted in left and right fields of view, the polarizingplate with its polarizing direction orthogonal to that of a polarizingplate on the LCD surface of the stereoscopic monitor, and drives theliquid-crystal plate with infrared rays for synchronization to open andclose a field of view for viewing the display in a synchronized manner.Furthermore, an applied voltage of the liquid-crystal plate mountedimmediately before the eyeglasses is controlled with a tilt-angle sensormounted on the eyeglasses to prevent crosstalk. The observer can viewstereoscopic video on the monitor equivalently to the reference window(with the same size and at the same position), and can also directlyview an actual scene to be shot at the same time.

According to this configuration, the observer (cameraperson) can obtainthe same sense of stereoscopy as that of a viewer of the stereoscopictelevision. Also, the cameraperson can observes the stereoscopic videoon the monitor at a magnification ratio equal to that of the actualscene (the magnification ratio is not restricted to be equal dependingon the shooting lens selected), and can also directly view an actualscene at the same time.

In the invention described in another, collimation patterns (left andright patterns superposing with each other to one) mainly formed ofvertical lines are superimposed by software on a display screen of astereoscopic monitor, thereby achieving viewability for stereoscopy, andthe monitor is optimal for the monitor of the above embodiment.

According to this configuration, since the position where the referencewindow is set can be visually recognized, it is very effective if theposition is displayed as being superposed on a monitor image of thestereoscopic television camera for use.

In the invention described in another embodiment, a stereoscopic videodisplaying apparatus (stereoscopic TV) is provided in which left andright videos based on standard stereoscopic video data are alternatelydisplayed on an LCD panel in a time-division manner, and also aninfrared-ray synchronizing signal sending apparatus for synchronizingeyeglasses for field-of-view separation is included.

According to this configuration, since the components of theconventional LCD-type TV can also be used, video can be easily madestereoscopic. Also, with standardization of stereoscopic video data,display can be made without adjustment even with different displaysizes.

In the invention described in another embodiment, a stereoscopic videodisplaying apparatus is provided, in which, with respect to anelectronic display, eyeglasses for field-of-view separation forseparating left and right fields of view and diopter correction lenses(plus-diopter lenses for focusing the eyes of the observer when viewinga subject at a distance shorter than a distance of distinct vision) aresuperposed with each other and in a state in which the display isobserved at the distance shorter than the distance of distinct vision,video is displayed on the display in a time-division manner alternatelywithin left and right field-of-view ranges determined by linesconnecting both ends of a reference dimension display screen of thestereoscopic video and the left and right eyes of the observer, and theleft and right fields of view are viewed by operating the eyeglasses forfield-of-view separation in synchronization with the left and rightvideos.

According to this configuration, even when a small-sized display isused, viewing can be made with a sense of stereoscopy equivalent to thatwhen a large-sized display is used.

In the invention described in an embodiment, a stereoscopic videodisplaying apparatus is provided, in which, with respect to anelectronic display, eyeglasses for field-of-view separation forseparating left and right fields of view are placed so as to be in astate observation at a distance longer than the distance of distinctvision, video is displayed on the display in a time-division manneralternately within left and right field-of-view ranges determined bylines connecting both ends of a reference dimension display screen ofthe stereoscopic video and the left and right eyes of the observer, andthe left and right fields of view are viewed by operating the eyeglassesfor field-of-view separation in synchronization with the left and rightvideos.

According to this configuration, although the apparatus becomes largerthan the stereoscopic video displaying apparatus described in anembodiment above, eyeglasses for diopter correction are not required fora person having a normal diopter (a person who can most easily view withthe naked eye at the distance of distinct vision).

In these stereoscopic video displaying apparatuses described in theabove embodiments, by fixing eyeglasses for field-of-view separation tothe display, no crosstalk occurs even when the observer tilts his or herhead.

In the invention described in another embodiment, a stereo photo printor stereo slide is provided which is of a type of recording two left andright screens so that they are placed side by side on one sheet or filmfrom standard stereoscopic video data.

According to this configuration, a stereo photo print or stereo slidehaving a spacing between the left and right screens being set in anoptimal state can be obtained.

Effects of the Invention

According to the invention described in claim 1 an embodiment, in theentire processing from imaging to display of stereoscopic video, anyvideo can be easily made stereoscopic with the existing devises andelement techniques. This can be put on existing media (for example,digital TV broadcasting, the Internet, and DVD) and also has anadvantage of easily switching from mono to stereo of video over TVbroadcasting, the Internet, and others.

According to the invention described in another embodiment, stereocameras can be standardized. This standardization can be achievedirrespectively of the size of image pickup device. Also, a finder is notnecessarily viewed stereoscopically.

According to the invention described in another embodiment, from a hugescreen size for showing in a movie theater to a small-sized television(the overlap display range) and, furthermore, a range where left andright small-sized displays are separately provided for display (thehorizontal side-by-side display range) can be displayed with the sameimage data. Even with different types and sizes of display, the samesense of stereoscopy can be obtained without adjustment. Therefore, itis extremely useful when stereoscopic TV broadcasting is generalized(implemented). This is because, although various specifications ofstereoscopic broadcasting on a transmission side can be unified, thoseon a receiving viewer side cannot be unified under various circumstances(for example, different sizes of TV to be placed are inevitable due toeconomic circumstances, the side of a room, and others).

The invention described in an embodiment is the one by applying theinvention described in another embodiment, and is directed to asubstantially only method in implementing stereoscopic TV broadcasting,and achieves the effect of digital TV broadcasting at its best. This isbecause digital TV broadcasting is transmitted into slots, and thecapacity of two channels of the current digital high-definitiontelevision can be transmitted simultaneously.

The invention described in an embodiment is the one by applying theinvention described in another embodiment, and is directed to asubstantially only method in implementing transmission and reception ofstereoscopic video data through a communication line. Even withdifference screen sized on transmission and reception sides, no process(no adjustment) is required on neither one of the transmission side andthe reception side, and also the same sense can be achieved as to thesense of stereoscopy and the size of a subject. Furthermore, integrationwith stereoscopic TV broadcasting is advantageously possible.

Also, a stereo photo print with left and right images placed side byside can be exchanged over the Internet. Further, similarly, an orderfor a stereo slide of a silver-salt scheme can be advantageously sent asimage data over the Internet.

According to the invention described in an embodiment, by setting thedistance between the optical axes of the left and right projectionlenses of the stereo projector in which paired left and right projectionunits are placed side by side and by setting the spacing betweenelectronic displays of the left and right projection units longer thanthe distance between the optical axes, the corresponding points of theimage at infinity based on standard stereoscopic video can be reproducedas being in a predetermined spacing equal to the interpupillary distanceirrespectively of the screen size. Also, irrespectively of theprojection screen size, the left and right videos can be viewedequivalently to the reference dimension display screen. Thus,“operation” at the time of projection is focus adjustment, and even astereo projector can be handled equivalently to a mono projector. Thisproblem of handling ability is a very important element in widespread tothe public.

Also, by setting the projection distance of the reference dimensiondisplay screen longer than a recommended view distance (an optimumdistance when the reference dimension display screen is viewed. Forexample, in FIG. 1, 2.5 meters), it can be avoided for the projectorfrom becoming an obstruction at the time of viewing.

According to the invention described in an embodiment, by setting thedistance between the optical axes of the left and right projectionlenses of the stereo projector in which paired left and right projectionunits are placed side by side at a human interpupillary distance and bysetting the spacing between electronic displays of the left and rightprojection units longer than the distance between the optical axes, thecorresponding points of the image at infinity can be reproduced as beingin a predetermined spacing equal to the interpupillary distanceirrespectively of the projection distance and, also, irrespectively ofthe projection screen size, the left and right videos can be viewedequivalently to the reference dimension display screen. Furthermore, bysetting the projection distance of the reference dimension displayscreen shorter than the recommended view distance (an optimum distancewhen the reference dimension display screen is viewed. For example, inFIG. 1, 2.5 meters), the depth dimension of aprojection-unit-incorporated-type stereoscopic video displayingapparatus, such as a rear-projection TV, can be advantageously madesmall (thin).

A feature of the invention described in an embodiment is that theinvention can be achieved with a simple structure only with aninfrared-ray synchronizing apparatus being coupled to a mono projectorof a conventional type.

In the invention described in an embodiment, in structure, polarizingfilters are mounted on a rear-projection-type mono television formed ofa DMD unit for alternately displaying left and right videos and, withliquid-crystal eyeglasses, the left and right fields of view aresimultaneously opened and closed for separate viewing. Also, with thescreen size being set as the reference dimension size, it is enough toalternately display the left and right images based on the standardstereoscopic video data on the DMD, no non-display zone is required tobe provided at a portion of a small element, such as the DMD, and allpixels of the DMD can be effectively used. Also, only one projectionlens is needed. And, by setting the projection distance of the referencedimension display screen shorter than the recommended view distance, thedepth dimension of the rear-projection-type stereoscopic video displayapparatus (stereoscopic TV) can be advantageously made small.

According to this configuration, even in the case of a stereoscopictelevision, implementation can be achieved with an approximately samestructure as that of a conventional DMD-type projection television (of amono type), and therefore the television can be inexpensively produced.

In the invention described in an embodiment, the DMD unit of theinvention described in another embodiment is replaced by an LCOS unit.

According to this configuration, since light beams emitted from the LCOSunit are polarized, no polarizing filter is required. Therefore, notonly the price can be reduced by the cost of the filter, but also a lossin light amount due to the polarizing filter can be reduced.

In the invention described in an embodiment, subsequent to thepolarizing filter of the rear-projection-type television formed of theDMD projection unit described in another embodiment above, aliquid-crystal cell and a λ/4 plate are disposed in this order foralternately displaying left and right videos; by applying a voltage tothe liquid-crystal cell in synchronization with a display of the DMD andalternately inputting linear polarizing light with its amplifyingdirection at an angle of ±45 degrees with respect to a fast axis of theλ/4 plate, circular polarizations in opposite counterclockwise andclockwise directions are achieved. The observer separately views theleft and right fields of view uses circular-polarizing eyeglasses inreverse counterclockwise and clockwise directions for separate viewingof the left and right fields of view.

According to this configuration, although the left and right videos arealternately displayed in a time-division manner, synchronization of theeyeglasses for viewing is not required. Therefore, not only a reductionin cost of the eyeglasses for viewing, but also removal of inconvenienceof mounting a battery on the eyeglasses can be achieved. Furthermore, ina projection-type television, the diameter of each of the polarizingfilter, the liquid-crystal cell, and the λ/4 plate can be advantageouslysmall so as to be approximately equal to the diameter of the lens forprojection.

In the invention described in an embodiment, the DMD unit described inanother embodiment above is replaced by an LCOS unit.

According to this configuration, since light emitted from the LCOS unitis polarized, no polarizing filter is required. Therefore, a loss inlight amount is reduced.

A feature of the invention described in an embodiment is thatstereoscopic video is displayed on a stereoscopic monitor of astereoscopic television camera, and the stereoscopic video on themonitor can be observed in the same size as the actual scene to be shot.Therefore, the cameraperson can view stereoscopic video with the samesense as that of the stereoscopic video being observed by the viewer.Furthermore, the actual scene can be directly viewed at the same timewhen the stereoscopic video on the monitor can be viewed.

According to this configuration, the cameraperson can always observe theshot recording or the transmitted stereoscopic video on the monitor and,at the same time, directly view the actual scene for comparison.Furthermore, whether in mono or stereo, when moving pictures are shot,it is important to know the progress of situations simultaneously at thetime of shooting. Therefore, an operational effect of this televisioncamera configured so as to allow an actual scene to be always viewedsimultaneously at the time of monitoring is enormous.

A feature of the invention described in an embodiment is thatcollimation patterns are displayed by software in a superimposing manneron a monitor of the stereoscopic imaging apparatus for simultaneousstereoscopy as being superposed with stereoscopic video, therebyimproving viewability of determining whether the sense of stereoscopy isexcellent.

According to this configuration, a shooting person can instantaneouslydetermine whether the sense of stereoscopy is appropriate in shootingstereoscopic video.

In the invention described in an embodiment, it is enough only toalternately display left and right videos of stereoscopic videos basedon standard stereoscopic video data on a conventional liquid crystal TVin a time-division manner and, at the same time, send an infrared-raysynchronizing signal for eyeglasses for field-of-view separation.

According to this configuration, a stereoscopic video displayingapparatus can be most easily achieved.

A feature of the invention described in an embodiment is that anelectronic display that alternately displays standard stereoscopicvideos in a time-division manner and the eyeglasses for field-of-viewseparation are fixed to each other to prevent the occurrence ofcrosstalk, and also eyeglasses for diopter correction are placed so asto observe at a position at a distance shorter than the distance ofdistinct vision.

According to this configuration, with the display and the eyeglasses forfield-of-view separation being fixed to each other, even when theobserver tilts his or her head, there is no fear of occurrence ofcrosstalk. Also, by mounting the eyeglasses for diopter correction,observation is possible at a position at a distance shorter than thedistance of distinct vision, and stereoscopic video can be observed witha large screen (reference dimension display screen) even a small displayis used.

Also, this configuration is very effective when used as a finder(monitor) of a stereoscopic video imaging apparatus. This is because theouter shape can be made small-sized, portability and handling abilityare excellent and, in addition, since light-shielded from externallight, the finder has an improved viewability under a brightenvironment, such as outdoors in the daytime.

A feature of the invention described in an embodiment is that anelectronic display that alternately displays standard stereoscopicvideos in a time-division manner and the eyeglasses for field-of-viewseparation are fixed to each other to prevent the occurrence ofcrosstalk, and also the eyeglasses for field-of-view separation areplaced at a position so as to allow observation at a distance longerthan the distance of distinct vision of the display.

According to this configuration, no eyeglasses for diopter correctionare required. Eyeglasses for diopter correction normally used by theobserver himself or herself (for near sight, long sight, or presbyopia)or the like may be used, or viewing may be performed with the naked eye.

Furthermore, a feature of the inventions described in embodiments isthat the observer does not wear eyeglasses for field-of-view separation.Although only one person can view with these stereoscopic videodisplaying apparatuses, for example, in public setting-up situations,sharing things in direct contact with the skin, such as eyeglasses forviewing (for field-of-view separation), is not preferable in view ofsanitation.

A feature of the invention described in an embodiment is that left andright images of a stereoscopic photograph can be recorded so as to beplaced side by side on one sheet.

According to this configuration, even with different formats (screensizes), a stereo photo print or stereo slide can be easily created withan optimal screen spacing.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 A conceptual diagram of stereoscopy of the present invention.

FIG. 2 A diagram of a relation between a reference dimension displayscreen (a large-sized stereoscopic TV depicted) in FIG. 1 and a stereocamera that sends standard stereoscopic video data.

FIG. 3 A detailed descriptive diagram of FIG. 1.

FIG. 4 A descriptive diagram when wide-angle shooting lenses are mountedon the stereo camera of FIG. 2(b).

FIG. 5 A descriptive diagram when long-focus shooting lenses are mountedon the stereo camera of FIG. 2(b).

FIG. 6 A descriptive diagram of a stereo projector with two, left andright projection units provided side by side.

FIG. 7 A descriptive diagram of a stereo projector with a singleprojection unit.

FIG. 8 A descriptive diagram of a rear-projection-type stereoscopictelevision for linear polarization time-division display with a singleprojection unit.

FIG. 9 A descriptive diagram of a rear-projection-type stereoscopictelevision for circular polarization time-division display with a singleprojection unit.

FIG. 10 A descriptive diagram of a stereoscopic television cameraallowing a stereoscopic image to be observed on a stereoscopic monitorand also an actual scene to be viewed at the same time.

FIG. 11 An embodiment of a collimation pattern for display on thestereoscopic monitor.

FIG. 12 A perspective view of a stereoscopic video displaying apparatus.

FIG. 13 A section view of eyeglasses for field-of-view separation andeyeglasses for diopter correction for the stereoscopic video displayingapparatus of FIG. 12.

DESCRIPTION OF NUMERALS

-   B human interpupillary distance-   L distance to a reference dimension display screen-   E_(L) left eye-   E_(R) right eye-   D display-   I_(∞) image at infinity-   W_(D) width of the display-   E_(ref) display of equivalent reference window (reference dimension    display screen)-   W_(ref) reference window-   W_(W) reference window width-   S image pickup device-   I_(ref) image in the reference window on the image pickup device-   α a view angle-   F focal length-   W_(S) width of the image pickup device-   D_(S) spacing between left and right image pickup devices-   O_(∞) infinity body-   Φ optical axis of a stereo camera-   D₀ display in reference dimensions-   D₁ display smaller than reference dimensions within an overlap    display range-   D₂ display or stereo slide within a horizontal side-by-side display    range-   W_(P0) width of the display D₀-   W_(P1) width of (a part of) the display D₁-   W_(P2) width of each of the left and right displays-   D_(P1) spacing (picture distance) between left and right displayed    on the display D₁-   D_(P2) placement spacing between the left and right displays or    picture distance of the stereo slide-   L₀ set distance in reference dimensions-   L₁ distance to the display D₁-   L₂ set distance to the display D₂ or the stereo slide within the    horizontal side-by-side display range-   L_(X) boundary point (in principle) between the horizontal    side-by-side display range and the overlap display range-   W_(ref)′ matching point between left and right shooting fields of    view when wide-angle lenses are mounted-   W_(ref)″ matching point between left and right shooting fields of    view when long-focus lenses are mounted-   P_(L) display range of a left screen of a screen size larger than    the reference dimensions-   R_(R) display range of a right screen of a screen size larger than    the reference dimensions-   S₀ screen at a reference dimension display screen position-   S₁ screen positioned at a short distance (1 meter)-   S₂ screen positioned at a distance where left and right videos are    placed side by side-   S₃ screen positioned far away from the reference dimension display    screen position-   60 projector-   61 projection lens-   62 display-   D_(D) spacing between the displays-   W_(D) display width-   θ projection angle-   71 screen equivalent to the reference dimension display screen-   72 projection lens-   73 display-   0 point of application of the projection lens-   X position (optical-axis extending point) where a corresponding    point of an image at infinity is to be displayed-   81 DMD or LCOS display (projection) unit-   82 projection lens-   83 polarizing filter-   84 transmission screen-   85 eyeglasses for stereoscopic video viewing-   91 DMD or LCOS display (projection) unit-   92 projection lens-   93 polarizing filter-   94 liquid-crystal cell-   λ/4 plate-   96 transmission screen-   97 circular-polarizing eyeglasses-   100 reference window (virtual field-of-view frame)-   101 stereoscopic monitor of the stereo TV camera-   102 stereo TV camera-   103 eyeglasses for stereoscopic video viewing-   104 cameraperson-   CP collimation pattern-   121 display-   122 board-   123 housing-   130 eyeglasses for field-of-view separation-   131 liquid-crystal plate-   132 polarizing plate-   133 eyeglasses for diopter correction

BEST MODES FOR CARRYING OUT THE INVENTION

A feature of the present invention is that stereoscopic video data canbe shared for use even with different sizes of image pickup device of astereo camera and different display ranges and screen sizes ofstereoscopic displaying apparatus, and a reference window is set at thetime of shooting so as to make a depth perception and dimensions ofevery stereoscopic video commonly recognized. And, this reference windowis shot as field-of-view frames (left and right image frames), and issent as reference stereoscopic video data necessary for display. Then,on a display side, the standard stereo video data is displayed on ascreen in reference dimensions equivalent to the reference window on ashooting side, thereby reproducing a high-fidelity sense of stereoscopy.

For example, in FIG. 2, when it is assumed that a width of a referencewindow W_(ref) . . . W_(W),

a width of an image, I_(ref(L)) and I_(ref(R)), within the referencewindow projected onto the respective image pickup device having a widthW_(S), and

a display screen width in reference dimensions . . . W_(D),

a shooting magnifying power r is r=W_(S)/W_(W),

a display magnifying power R is R=W_(D)/W_(S), and

r×R=1. According to the equations above, it can be understood thatmaking image data sent from the stereo camera as standard stereoscopicvideo data is easy, irrespectively of the width W_(S) of the imagepickup device.

First Embodiment

FIG. 1 is a conceptual diagram of stereoscopy. With a large-sizedstereoscopic TV depicted in the drawing being taken as a television witha standard dimension display screen (a display width of 1800 mm),display screens of various sizes and their arrangement have a relationdepicted in the drawing.

FIG. 3 illustrates dimensions and an arrangement relation in FIG. 1 inmore detail. In FIG. 3, in contrast to an actual dimensional ratio,representation is shown at a dimensional ratio that increases as it iscloser to the observer's position. This is to avoid congestion inplotting.

In FIG. 3, a distance L_(X) from the eyes of an observer to a boundarybetween a horizontal side-by-side display range and an overlap displayrange depicted in the drawing has a relation of L_(X)=L₀/(1+W_(P0)/B),and

-   -   when it is assumed that L₀=2500 mm and W_(P0)=1800 mm and    -   when an interpupillary distance dimension is B=58 mm,        L_(X)=2500/(1+1800/58)=78.04 mm, and    -   when the interpupillary distance dimension is B=72 mm,        L_(X)=2500/(1+1800/72)=96.15 mm.

In the horizontal side-by-side display range, a barrier wall is requiredfor partitioning into left and right fields of view, and an actual viewdistance has a limit of approximately 75 mm. Also, since 75 mm is verynear compared with a distance of distinct vision, a loupe for diopteradjustment is required. A loupe with a focal length slightly longer thanthe viewing distance is proper. Therefore, in this case, an appropriatefocal length of the loupe for use is approximately 80 mm.

Also, although the interpupillary distance dimension (on a stereo base)B varies to some degree among observers, when the view distance is long(overlap display range), some difference between the spacing betweenleft and right corresponding points of an image at infinity and theinterpupillary distance dimension B may be ignored.

And, in the horizontal side-by-side display range, although a margin ofa difference with the interpupillary distance dimension B is small, thedifference is mitigated by adjusting the spacing between diopteradjusting lenses.

A spacing between left and right screens, that is, a picture distance,has the following relation with the horizontal interpupillary spacing Band a distance L₀ to a display D₀ in reference dimensions. A picturedistance D_(PN) of a display D_(N) disposed at an arbitrary distanceL_(N) has a value of D_(PN)=B(1−L_(N)/L₀).

A width W_(P0) of each of left and right screens is proportional to thedistance from the eyes of the observer. Since left and right visualangles α depicted in the drawing formed by interposing the display D₀between light beams entering each eye are the same, respective apparentscreen widths depicted in FIG. 3 have a relation ofW_(P0)=W_(P1)=W_(P2), and therefore the screens can be viewed as havingthe same size.

As described above, by displaying standard stereoscopic video data on aTV with the reference dimension display screen (a large-sized TVdepicted in FIG. 1) in a relation and arrangement depicted in FIG. 1,common data can be used in all display ranges from the overlap displayrange with left and right images superposed thereon to the horizontalside-by-side display range having separate left and right displaysurfaces. In this case, on each display depicted in the drawing, it isenough to only arrange and display the standard stereoscopic video data(at a position and with a width) under conditions independently definedfor left and right.

FIG. 2 is a diagram for describing a stereo camera as a means obtainingstereoscopic image data in the relation and arrangement depicted inFIG. 1. FIG. 2(a) is a diagram of a state exactly the same as the stateof stereoscopy of FIG. 1, and FIG. 2(b) is a relation diagram in thecase of using a stereo camera. Now, when it is assumed that a displayE_(ref) of an equivalent reference window depicted in FIG. 2(a) is adisplay of the television with a reference dimension display screen ofFIG. 1 (the large-sized stereoscopic TV depicted in FIG. 1), a referencewindow W_(ref) is set to the stereo camera of FIG. 2(b), and the spacingbetween left and right shooting lenses of the camera is theinterpupillary distance dimension B, a conjugate relation establishesbetween a distance from the display E_(ref) of the equivalent referencewindow of FIG. 2(a) to left and right eyes E_(L) and E_(R) of theobserver and a distance from the reference window W_(ref) having a widthW_(W) to left and right shooting lenses L_(L) and L_(R). Therefore,image data on the image pickup device disposed in each of the left andright view angles α is the same as that when a person actually observesthe television with the reference dimension display screen of FIG. 1(the large-sized stereoscopic TV depicted in the drawing). Also, thesize (width) of the image pickup device disposed in the view angle α isdetermined by the position of the image pickup device in an optical-axisdirection.

In FIG. 2(b), the width W_(S) of the image pickup device is calculatedby W_(S)=W_(W)×f/L. Also, the spacing between the left and right imagepickup devices (picture distance in an inverted image state), that is,D_(s) depicted in the drawing, is calculated byD _(S) =B(1+f/L), which is longer than the spacing between the left andright shooting lenses=human interpupillary width B.

An image projected on each image pickup device is in an inverted state.When the image is rotated at 180 degrees at each of the left and rightpositions for erection, the spacing between the left and right screens,that is, the picture distance (on a display side=an erect image state),becomes shorter than the human interpupillary distance B. Also, twotriangles (two triangles partially overlapping each other) eachconfigured of the reference window W_(ref) depicted in FIG. 2(b) andlines each passing through a principal point of a corresponding one ofthe left and right shooting lenses, the lines between which the windowW_(W) of the reference window W_(ref) is interposed, and two trianglesconfigured of lines each passing though the principal point of acorresponding one of the left and right shooting lenses, the linesbetween which both ends of a corresponding one of the left and rightimage pickup devices S, and a surface of the image pickup device itselfare similar figures symmetric with respect to the principal point of acorresponding one of the left and right shooting lenses. Also, sinceleft and right units are symmetric with reference to a center line 0depicted in the drawing, when the drawing is folded along the centerline 0 on the paper as a folding line, left and right optical axes Φ(L)and Φ(R) match each other, and the left and right axes overlap eachother. Therefore, stereoscopic videos shot by the stereo camera of FIG.2(b) are displayed at the same screen position on the TV with thereference dimension display screen of FIG. 1 (the large-sizedstereoscopic television depicted in the drawing) alternately in atime-division manner or in a manner such that they are simultaneouslysuperposed by polarization or the like, and when the left and rightscreens are viewed with the left and right eyes through eyeglasses forfield-of-view separation, the corresponding points of the image atinfinity are displayed by itself at the human interpupillary distance.Thus, stereoscopic video in an optimum state can be reproduced. Here,for projection at the same position with reference dimensions, nospecial measures are required, and it is enough to display an image onthe image pickup device S depicted in FIG. 2(b) at a display magnifyingpower of W_(D)/W_(S), which is a simple ratio between the screen widthW_(D) of the display D and the width W_(S) of the image pickup device.

Also, each of the left and right screen widths of respective sizesdepicted in FIG. 1 is determined at a ratio between a distance ofarrangement of each displaying apparatus and a distance to the TV withthe reference dimension display screen (in FIG. 3, L₁/L₀=W_(P1)/W_(P0)).Therefore, since the left and right display screen widths are easilycalculated because of having a simple ratio.

And, as depicted in FIG. 1, in stereoscopic video, the correspondingpoints at infinity should be displayed in all regions with the humaninterpupillary distance spacing. Thus, infinity=interpupillarydistance=distance between optical axes of the left and right shootinglenses and, since light beams from the corresponding points at infinityentering the left and right shooting lenses of the stereo camera areparallel to each other, the corresponding points of the image atinfinity projected onto the image pickup devices have a space equal tothe distance between optical axes. Therefore, even with any displaysize, the spacing between the corresponding points at infinity betweenthe left and right display screens=the human interpupillary distance canbe set only by setting a corresponding center position of the opticalaxis of each of the left and right shooting lenses on the left and rightimage pickup devices at a position so that the spacing between the leftand right positions on the display screen is equal to the humaninterpupillary distance spacing. That is, even with a stereoscopicdisplaying apparatus of any screen size, with reference to the left andright optical axes of the stereo camera, a spacing corresponding to thespacing between the left and right optical axes of the imaging unit isdisplayed on left and right of a reproduction screen so as to have adimension equal to the human interpupillary distance.

FIG. 4 is a diagram of a state when the shooting lenses of the camera inthe state depicted in FIG. 2 are replaced by wide-angle shooting lenses.To shoot a subject of the same size at a wide angle, the workingdistance is short. Also, to form an image on an image pickup device ofthe same size, the focal length of each shooting lens is short. Asdepicted in FIG. 4, when the lenses are replaced by shooting lenses of ashort focal length, the distance at which left and right fields of viewmatch each other in stereoscopy is also short. If an actual scene isdirectly viewed by the naked eye, when infinity (infinity in a sense ofphoto shooting) is included in a field-of-view frame W_(ref)′ at aposition depicted in FIG. 4 with a broken line, it is impossible to viewa near-distance subject and a long-distance subject at the same time instereoscopy (when a person views an actual scene, it seems that a narrowfield of view is instantaneously viewed at every moment forintracerebral process, thereby allowing viewing in practice, but thiscauses fatigue to optic nerves). However, when stereoscopic image datashot by a camera in this state (shooting is performed by shooting lensesof a short focal length and the left and right fields of view match eachother at a short shooting distance) is viewed with a stereoscopictelevision with a reference dimension display screen depicted in FIG. 1,the state of stereoscopy is excellent. When the reference windowW_(ref)′ depicted in FIG. 4 with the broken line is set, if an actualscene is directly viewed from that window, which is assumed to be real,parallax between a near-distance scene and a long-distance scene islarge, and therefore it is impossible in stereoscopy to view the leftand right fields of view as one. However, this stereoscopic video datais viewed with each displaying apparatus in the state of settingsdepicted in FIG. 1, the reference window W_(ref)′ depicted in FIG. 4with the broken line can be viewed as being far away to a position of areference window W_(ref) depicted in the drawing with a solid line,thereby allowing stereoscopy normally. Therefore, the use of wide-angleshooting lenses is advantageous because shooting can be performed in anarrow place by getting closer to a subject.

FIG. 5 illustrates an example of the use of lenses with a long focallength, conversely to the case of FIG. 4. When the focal length of theshooting lenses is long, the left and right shooting fields of viewmatch each other at a position far away from a standard view distance (aposition represented by a broken line). Also in this case, however, whenviewing is performed with the displaying apparatus depicted in FIG. 1,the reference window W_(ref)″ actually positioned far away at theposition represented by the broken line can be viewed as being near aposition of the field-of-view frame W_(ref) represented by the solidline.

According to the description based on FIG. 4 and FIG. 5 above, the useof zoom lenses can be naturally implemented. Even when the focal lengthof the shooting lenses is varied anyway, the width and spacing of theimage pickup devices fitting to the reference dimension display screencalculated by the above equations based on FIG. 2 suffice (in practice,a largish width of the image pickup devices may be used to set a readrange). Then, even when the focal length of the shooting lenses of thestereo camera is changed, it is enough to only set, for example, eachcondition depicted in FIG. 1, in a predetermined state in thestereoscopic television on a viewing side. This is because light beamsentering the left and right shooting lenses from the corresponding pointat infinity are parallel to each other and also the distance between theoptical axes of the shooting lenses is set at the human interpupillarydistance. For this reason, the spacing between the corresponding pointsat infinity projected onto the left and right image pickup devices isequal to the human interpupillary distance.

Even when the focal length of the shooting lenses is changed withrespect to the same stereo camera, the width of and spacing between thepaired left and right image pickup devices are constant. Therefore, whenthe focal length of the shooting lenses is changed, the shootingdistance where the left and right fields of view match each other ischanged. In stereoscopic video, in any cases, a shooting state in whicha subject at a distance shorter than the distance where the left andright fields of view match each other is within a shooting field of viewis not preferable in general. In a stereo camera, even if a finder issubjected to stereoscopy, it is extremely difficult to visuallyrecognize whether or not a subject within a shooting field of view iswithin a distance where the left and right fields of view match eachother. By displaying collimation patterns depicted in FIG. 11 on theleft and right screens of the finder in a superposed manner, viewabilitycan be improved.

A stereo projector 60 depicted in FIG. 6 includes a pair of left andright projection lenses 61L and 61R set with a human interpupillarydistance spacing. Furthermore, displays 62L and 62R having a width W_(D)are placed with a spacing D_(D) slightly longer than the spacing of theleft and right projection lenses 61, thereby matching left and rightprojection screens each other on a screen S₀ equivalent to the referencedimension display screen. Thus, only with focusing on the screen at anarbitrary distance, the projected images are displayed under the sameconditions as those in the state depicted in FIG. 1, and a sense ofstereoscopy can be obtained by observing from an appropriate viewingdistance.

As long as the positions of the displays 62L and 62R are each at aposition of an angle of projection θ depicted in the drawing, the sizeof the width W_(D) of the display 62 is not restricted, and isdetermined by a sum of a focal length f and a focus control amount Δf ofthe lenses, that is, f+Δf, from screens S₀ to S₃ of the projectionlenses, that is, at the entire projection distance. Therefore, the angleof projection θ α depicted in FIG. 6 is set at the same angle as theangle of view a depicted in FIG. 2(b), it is not necessary to set thewidth W_(S) of the image pickup devices S depicted in FIG. 2(b) and thewidth W_(D) of the display 62 depicted in FIG. 6 at the same width.

However, in the drawings, in practice, the placement position (distance)of the projector and the view distance become equal to each other, andthe projector itself becomes an obstruction. This can be solved bymultiplying the placement distance (screens S₀ to S₃) of the projectorby n (n>1). Therefore, the relation between the angle of projection θand the angle of view α depicted in FIG. 2(b) described above is notθ=α, but a relation of θ<α holds.

FIG. 7 is a descriptive diagram when the stereo projector of FIG. 6 inwhich two projection units are placed side by side is modified with asingle unit. Left and right videos displayed on left and right displays73L and 73R depicted with broken lines form an image by left and rightprojection lenses 72L and 72R represented by broken lines on a screen71, with left and right width directions being matched each other. Theleft and right projected screens match each other on the screen 71although a distance between optical axes of the left and rightprojection lenses is set at 65 mm, which is equal to the dimension of ahuman interpupillary distance, because the spacing between the left andright displays 73L and 73R is set longer than the distance between theoptical axes.

A triangle a, O_((R)), b and a triangle f, O_((R)), e depicted in FIG. 7with broken lines are similar figures with the point O_((R)) as a pointof symmetry. Similarly, a triangle a, O_((L)), b and a triangle d,O_((L)), c depicted with broken lines and a triangle a, O_((C)), b and atriangle h, O_((C)), g depicted with solid lines are similar figures,respectively, with the point O_((L)) and the point O_((C)) each as apoint of symmetry. Therefore, line segments c-d, g-e, and e-f are equalto each other. Therefore, when the left and right projection lenses 72_((L)) and 72 _((R)) depicted with broken lines are moved to anintermediate position of 72 _((C)) represented by a solid line, thedisplays 73 _((L)) and 73 _((R)) depicted with the broken lines aresuperposed with an intermediate position 73 _((C)) represented by asolid line. Also, as for left and right videos to be displayed on thedisplays 73 _((L)) and 73 _((R)), the left and right videos aredisplayed alternately in a time-division manner by using a singleprojection unit formed of the projection lens 72 _((C)) and the display73 _((C)), this is equivalent to a projector with two left and rightprojection units placed side by side. And, an image X_(L) on the display73 _((L)) and an image X_(R) on the display 73 _((R)) each with respectto a corresponding point of an image at infinity formed on the screen 71with a dimension equal to the distance between the optical axes of theleft and right projection lenses are alternately displayed on thedisplay 73 _((C)) so as to have a positional relation represented by →.The left and right positions are reversed because an inverted image isdisplayed on a display for displaying an original image in the projectorand is reversed by the projection lenses.

Here, the corresponding points of images at infinity are depicted so asto be viewed at a horizontally symmetric position as depicted, that is,at a screen center position in a state of stereoscopy. However, anactual image at infinity is not restricted to be at the screen center,and this plotting is for convenience of description. However, lightbeams emitted from the same point of a subject at infinity enter theleft and right eyes so as to be parallel to each other. Therefore, eventhis plotting is assumed to be understood in general.

FIG. 8 illustrates an example of application of the stereoscopic videodisplaying apparatus with a single projection unit described above withreference to FIG. 7. A stereoscopic video displaying apparatus 80(stereoscopic television) is of a rear projection type for projectingvideo to be displayed on a DMD 81 by a projection lens 82 onto atransmission screen 84 (rear surface). On a front surface of theprojection lens 82, a polarizing plate 83 is placed. In this state, whenleft and right videos are alternately displayed by the DMD 81 in atime-division manner, the left and right videos are alternatelydisplayed on the transmission screen 84 in time series with the samestate of polarization. When this stereoscopic video is viewed with theeyeglasses for stereoscopic video viewing described above, stereoscopycan be achieved with the left and right fields of view separated fromeach other.

Also, when LCOS is used as a display device in place of DMD, since lightbeams reflected on LCOS are polarized, the polarizing plate 83 depictedin FIG. 8 is not required.

FIG. 9 illustrates a stereoscopic video displaying apparatus 90(stereoscopic television), in which a DMD rear projection unit 91 has aprojection lens 92 with its front surface having a polarizing plate 93placed thereon, and with its front surface having a liquid-crystal cell94 placed thereon, and further with its front surface having a λ/4 plate95 placed thereon, thereby alternately displaying stereoscopic left andright videos on the DMD 91 based on standard stereoscopic video data anddriving the liquid cell in synchronization with the display image of theDMD 91 for control so that light enters with a relation in which apolarizing direction with respect to a fast axis of the λ/4 plate 95 is45 degrees and −45 degrees, thereby alternately displaying stereoscopicvideo on the transmission screen 96 with circular polarization inclockwise and counterclockwise directions. In this case, by usingcircular-polarizing eyeglasses for viewing, no crosstalk occurs evenwhen the eyeglasses are tilted.

Also, in the apparatus 90 described above, when LCOS is used in place ofDMD, the polarizing plate 93 is not required.

In a stereo camera for television broadcasting, it is preferable to beable to observe a shooting field of view reflected on a stereoscopicfinder and directly view an actual at the same time. To achieve such astereoscopic finder (monitor), for example, the liquid-crystal displayof a 12-inch width depicted in FIG. 1 is mounted on a stereoscopictelevision camera. The 12-inch-size monitor is among large ones as acamera monitor but, as depicted in the drawing, viewing can be made froma position of 350 mm. In this case, left and right images arealternately displayed in a time-division manner. At the same time,infrared rays for synchronization are sent from a synchronizing signalsending apparatus mounted on the display (not shown). And, on the leftand right sides of eyeglasses for stereoscopic video viewing in whichleft and right fields of view are separated, left and right polarizingplates identical to each other are mounted, respectively. Furthermore,on its front surface, a liquid-crystal plate is mounted. Also, on theeyeglasses, a tilt-angle sensor is mounted. Left and right light beamsalternately discharged from the LCD described above are polarized lightbeams identical to each other and in a predetermined direction. When thepolarizing plates of the eyeglasses described above are set in adirection orthogonal to a direction of interrupting the polarized lightbeams discharged from the LCD, the left and right fields of view of theeyeglasses are closed to become dark. The state of the fields of view ischanged in a manner such that a polarizing direction of incident lightfrom the LCD is optically rotated by 90 degrees or 270 degrees by theliquid-crystal plate mounted on the front surface to cause both of theleft and right fields of view to be in an open state and viewedbrightly. When a voltage is alternately applied to the liquid-crystalplates mounted on the front surface of the eyeglasses with infrared rayssent in synchronization with a display image on the LCD, the liquidcrystal becomes in a tension state with that voltage. As for polarizedlight discharged from the LCD, the polarizing direction is kept as itis, and light-shielding is made by the liquid-crystal plates of theeyeglasses to cause the fields of view to be dark. At the same time,when a voltage is alternately applied to the liquid-crystal plates ofthe eyeglasses in synchronization with the LCD with infrared rays, theleft and right fields of view are alternately opened and closed, and theleft and right fields of view for viewing the LCD is separated, therebyallowing stereoscopy. Also, when the eyeglasses are tilted, a relativedirectional relation between the LCD and the polarizing direction of theeyeglasses is distorted to cause crosstalk. The crosstalk is preventedby controlling and correcting the applied voltage with the tilt-anglesensor. Here, in the electronic imaging apparatus, the finder is notrequired to be integrated with the camera. For example, when a stereocamera configured of a pair of left and right shooting lenses and a pairof left and right image pickup devices and a notebook personal computerare connected to each other via a USB cable or the like, the PC itselfserves as a finder.

FIG. 10 illustrates an embodiment of the stereoscopic television cameradescribed above, and a two-dot-chain line 100 depicted in the drawingrepresents a reference window, which has been described above. Thisreference window is substantially a field of view of the camera, and isa field-of-view frame virtually set on an actual scene to be shot by thestereo camera. This virtual field-of-view frame represents a stateequivalent to a state of viewing outer scenery from, for example, ahouse window or the like. However, since no frame is present in anactual scene, as a matter of course, a cameraperson 104 directly views,through eyeglasses for stereoscopic video viewing 103 over astereoscopic television camera 102, not only a shooting field of view(the reference window 100 depicted in the drawing) but also a sceneoutside the shooting field of view. Then, when casting an eye onto amonitor 101, the person can view stereoscopic video of the same size andsame sense of distance (the video can be viewed as such, although theactual display dimensions are different) as those of the referencewindow 100 on (in) the monitor 101.

A relation between the width of the monitor-purpose display 101 of FIG.10 and an appropriate viewing distance is such that, when it is assumedin FIG. 3 that L₁=350 mm, left and right display screen widths are:

-   -   for W_(P1), W_(P1)=W_(P0)×L₁/L₀, and    -   when it is assumed that W_(P0)=1800 mm and L₀=2500 mm,    -   each of the left and right display screen width W_(P1) is        W_(P1)=1800×350/2500=252 mm.

A spacing between the left and right screens, that is, a picturedistance, is represented by D_(P1) in FIG. 3, and

-   -   when D_(PN)=B(1−L_(N)/L₀) represented above, and    -   D_(P1)=B(1−L₁/L₀), and when the interpupillary distance is B=65        mm,    -   D_(P1)=65 (1−350/2500)=55.9 mm

The distance between the centers of the left and right image displayscreens, that is, the picture distance, is as described with FIG. 3 fordisplay, and the spacing between the corresponding points of images atinfinity is set at 65 mm, which is equal to the human interpupillarydistance, for display. In FIG. 3, D_(P1) (R) represents a screen forright and D_(P1) (L) represents a screen for left. At this time, thesize (entire width) of the display D₁ is:

a total of W_(P1) and D_(P1), and W_(P1)+D_(P1)=252+55.9=307.9 mm

This dimension is slightly longer than 12 inches, that is, 12×25.4=304.8mm, because the viewing distance itself is processed as a numericalvalue in steps of 10 mm for representation. Also, in practice, a bitlonger viewing distance poses no problem.

Also, conversely, when the viewing distance L₁ is calculated from thedisplay size,

when it is assumed in FIG. 3 that L₁=L₀(W_(P1)+D_(P1)−B)/(W_(P0)−B).

W_(P1)+D_(P1)=12″=304.8 mm,

B=65 mm,

W_(P0)=1800 mm, and

L₀=2500 mm, the viewing distance L₁ is

L₁=2500(304.8−65)/(1800−65)=345.53 mm.

Furthermore, to facilitate viewability of stereoscopy of the monitor ofthe stereoscopic television camera, a collimation pattern mainly formedof vertical lines is superposed and displayed by software on each of theleft and right images to be displayed. FIG. 11 is a detailed diagram ofa monitor 101 of the stereoscopic television camera 102 of FIG. 10. Onthe monitor 101 (display D₁), a collimation pattern is displayed bysoftware at a position so that each pattern and the left and rightimages superpose each other. As a matter of course, the collimationpatterns are displayed only on the finder, and image data sent from thestereo camera is imaged image data only.

When the liquid-crystal monitor 101 of the stereoscopic televisioncamera 102 described from p. 36, l. 20 to p. 40, l. 8 of Specificationis stereoscopically viewed through the eyeglasses for stereoscopic videoviewing 103, the state of adjusting the sense of stereoscopy can bevisually recognized. And, the stereoscopic video viewed on the monitorof this stereoscopic television camera allows the sense of threedimensions in exactly the same state as that of a viewer receivingstereoscopic broadcasting shot and sent by this stereoscopic televisioncamera and viewing stereoscopic television.

Furthermore, whether in mono or stereo, when moving pictures are shot,it is important to know the progress of situations simultaneously at thetime of shooting. Therefore, an operational effect of this televisioncamera configured so as to allow an actual scene to be always viewedwhile monitoring is enormous.

The stereoscopic video imaging apparatus described from p. 36, l. 20 top. 40, l. 25 of Specification is extremely effective, but the finder(monitor) portion is large, posing problems in hand-held shooting,portability, and others. Also, light shielding of the finder portion isincomplete, posing a problem in which it is difficult to view a finderimage in a bright shooting environment.

FIG. 12 is a perspective view of a stereoscopic finder with eyeglassesfor field-of-view separation fixed on a display, in which a display 121of a stereoscopic finder 120 and a board 122 holding eyeglasses forfield-of-view separation 130 are fixed by a casing 123. The display 121is an LCD, for example, and alternately displays left and right videosso as to display the left video at a P_(L) portion on a screen widthW_(D) depicted in the drawing and the right video in a P_(R) portionthereon depicted in the drawing and separates the left and right fieldsof view in synchronization with the eyeglasses for field-of-viewseparation 130 for stereoscopy. Since the field of view islight-shielded from external light with the casing 123, the display canbe clearly viewed even under a bright environment outdoors. Also, sincethe eyeglasses for field-of-view separation is fixed to the display,there is no fear of crosstalk even when the observer tilts his or herhead.

Irrespectively of either large or small size as described with referenceto FIG. 3, the finder (display) can be viewed equivalently to thereference dimension display screen, depending on how to display and theviewing distance. However, in consideration of tilt ability, a smallerdisplay size is preferable. When the display size is small, the distanceof viewing the display is shorter than the distance of distinct vision.When the observation distance is shorter than the distance of distinctvision, a diopter correction lens (plus diopter) depicted in FIG. 13 isrequired even for a person with normal vision. Also, with a movement(not shown) of a diopter correction lens 133 in an optical axisdirection, adjustment can be made according to the diopter of theobserver.

FIG. 13 is a configuration diagram of the eyeglasses for field-of-viewseparation 130 of the stereoscopic video displaying apparatus 120 ofFIG. 12 depicted above, and the eyeglasses are mainly formed of apolarizing plate 132 and a liquid crystal plate 131. When the display121 of the stereoscopic video displaying apparatus 120 of FIG. 12 is anLCD, display light is polarized light, and when the polarizing plate 132depicted in FIG. 13 is placed (on both left and right) in an orthogonaldirection in a state of light-shielding the polarized light mentionedabove with respect to amplifying direction of display light, the fieldof view is closed. And, when the liquid-crystal plate is placed ahead ofthe polarizing plate 132 depicted in the drawing, display light of theLCD is rotated by 90 degrees or 270 degrees to be in a state of openingthe field of view. In this state, when a voltage is applied to theliquid crystal plate 131, the twisted liquid crystal is linearlystrained and light passes though as it is without being rotated by theliquid-crystal plate 131, and therefore light is shielded by thepolarizing plate 132 to close the field of view. By applying a voltageto the liquid-crystal plate 131 depicted in FIG. 13 in synchronizationwith display of the display 121 depicted in FIG. 12, the left and rightfields of view are separated for stereoscopy. Here, in the descriptionabove, although the field of view is in a closed state when a voltage isapplied to the liquid-crystal plate 131 depicted in FIG. 13, if thepolarizing plate 132 is placed in the same direction as that of apolarizing plate on the surface of the display (LCD) 121 depicted inFIG. 12, the field of view is in an open state when a voltage is appliedto the liquid-crystal plate 131.

Here, when a non-polarizing material, such as an organic EL, is used asa display, if so-called shutter eyeglasses with one more polarizingplate further added to the front surface of the liquid-crystal plate 131of FIG. 13 are used, the operation goes the same. Also, when a dischargelamp that lights at commercial frequencies is viewed with the shuttereyeglasses, flicker occurs. However, the finder 120 of FIG. 12 isshielded from external light. Since light beams viewed through theeyeglasses for field-of-view separation 130 are light beams of thedisplay only, even if the eyeglasses for field-of-view separation 130 isshutter eyeglasses, flicker does not occur.

Here, in the description from p. 40, l. 26 to p. 43, l. 4 ofSpecification, the finder of the stereoscopic imaging apparatus isassumed, but this is merely an embodiment of the stereoscopic videodisplaying apparatus of another embodiment, and can be used as a normalstereoscopic video displaying apparatus. Also, the casing 123 of thestereoscopic video displaying apparatus 120 depicted in FIG. 12 may beother than that depicted in the drawing. For example, bellows, afoldable focusing hood as seen in conventional cameras, and others maybe used (not shown).

In the case of a stationary-type stereoscopic video displayingapparatus, the display size is desirably large to some extent. This isbecause, in general, the larger the display size, the easier to increaseresolution. When a large screen is viewed, if each observer useseyeglasses for field-of-view separation, many people can advantageouslyview at the same time. However, in consideration of a sanitation problemof reusing eyeglasses used by others in public environment, a techniqueof mounting eyeglasses onto a display for peering still has anadvantage. Even in this case, the display is desirably large to sameextent. And, when the position where the display is placed, that is, theview distance, is desirably at a distance longer than the distance ofdistinct vision. At a distance longer than the distance of distinctvision, the diopter correction lens 133 depicted in FIG. 13 is notrequired, and diopter correction eyeglasses normally used by eachobserver may be used, or no eyeglasses may be worn, according tosituations similar to those at the time of usually viewing something.

Conventionally, the electronic stereoscopic video imaging and displayapparatuses and stereo photographs with two screens placed side by sidehave pursued different paths. However, in recent years, with advance ofelectronic video (image) machines, there is a demand for handling bothas one, but it has not yet been fulfilled to date. To respond to thisdemand, the invention described in an embodiment of the presentapplication is directed to a technique capable of fabricating a stereophoto print of two-screen side-by-side mode from one frame (paired leftand right screens) projected on an electronic stereoscopic videodisplaying apparatus (for example, stereoscopic television) or freelyfabricating a stereo slide of two-screen side-by-side mode from standardstereoscopic video data shot by a digital stereo camera.

According to FIG. 1, when left and right images are placed in ahorizontal side-by-side display range depicted in the drawing and viewed(requiring diopter correction lenses because the viewing distance isextremely shorter than the distance of distinct vision), left and rightfields of view match each other at the position of the large-sizedtelevision depicted in the drawing, and it looks as if a large-sizedtelevision exists at the display position depicted in the drawing. FIG.3 is a detailed diagram of FIG. 1. When standard stereoscopic data isdisplayed on left and right screens (D₂ (L) and D₂ (R) depicted in thedrawing) placed side by side for display on the reference display D₀,the display screen becomes small, as a matter of course. Although thesize of the display screen is a matter of general concern even inconventional mono video, the problem that has not been considered is howto determine the spacing between the left and right screens

According to FIG. 3, when it is assumed that the placement distance ofthe display D₀ of a reference dimension display screen is L₀, theposition of the stereo print (slide) D₂ where left and right images areplaced side by side (viewing distance) is L₂, and a human interpupillarydistance is B, the spacing between the left and right screens (D_(P2)depicted in the drawing) of the stereo print (slide) is determined asD_(P2)=B (1−L₂/L₀).

Second Embodiment

The present invention actualizes stereoscopic television broadcastingand, in addition to that, allows stereoscopic video to be put on theInternet to present stereoscopic video of products for mail-orderselling or the like. Also, describing about handling of products withtheir stereoscopic video is more effective than demonstration of actualproducts. This is because actual products have to be exhibited even someof them are unmarketable, which poses a problem in space efficiency and,even if many products are exhibited, products actually marketable areusually very limited, thereby causing a risk of obsolescence of unsoldinventory. With an exhibition with stereoscopic video, the number ofproducts to be actually displayed in stores can be significantlyreduced.

Other than that, for the purpose of sale, it is effective to usestereoscopic video also for sale of automobiles and furniture. It isextremely effective not only for a salesperson to bring recorded videofor demonstration but also for over-the-counter sale. The reason forthis is that, since automobiles, furniture, and others require a vastexhibition space, many products cannot be exhibited. Also, it iseconomically impossible to prepare many high-priced products forexhibition and, furthermore, it may be impossible to present an actualuse scene of some actual products. This goes the same for sale ofapparel and others, and a fashion show can be presented as stereoscopicvideo.

Still further, in the example of sale of commodities described above,mobile exhibition is possible even for a large product, but inhousing-related exhibition, such as the one for a room of an apartment,mobile exhibition of an actual product is impossible. In this case, thepresent invention is very effective.

Described above are sales-related examples of application. Other thanthat, the present invention is very effective when used as a guide forsightseeing.

Furthermore, an example of application unique to stereoscopic video is aeducational training system. Description of various mechanicalinstruments and the structure and handling of aircraft is easier tounderstand with explanation with real pictures and stereoscopicanimation rather than with explanation of an actual instrument oraircraft.

Still further, an example of most effective application is in the fieldof medical education. For example, a first step in surgery as an internis to look at an operation near a person conducting it. In practice,however, it is impossible to place many onlookers around an operatingtable and the place may not be able to be actually viewed clearly evenby looking nearby. In this case, a commentator describes video shot by astereo camera (moving pictures are shot and recorded, and a necessaryportion is advanced frame by frame to be repeatedly viewed in slowmotion), and medical students can view it stereoscopically on a displayof a personal computer on each desk or on a large-sized TV. In aconventional projection-type stereoscopic screening system, clear imagescannot be obtained without a dark environment, and therefore it isrequired to reduce lighting or shield light from a window, which is notappropriate in an educational site. According to a stereoscopictelevision system of the present invention, sharp stereoscopic video canbe viewed even under a bright environment.

Still further, in medical care, support from a medical specialist can beobtained with stereoscopic video through a communication line from aremote place, which contributes to telemedicine.

Here, in an example of medical application, a connection with astereoscopic endoscopic camera allows stereoscopic viewing of the insideof a body cavity. In this case, a feature of the stereoscopic televisionsystem of the present application is such that, during stereoscopicviewing with a television (display), a line of sight can be moved to asurrounding environment with the state unchanged (without removal ofeyeglasses for stereoscopy). Also, according to the liquid-crystaldisplay, viewing can be made without reducing lighting.

Still further, stereoscopy is required especially in the field of atomicenergy. To protect operators and surrounding environments fromradioactivity, the present invention is expected to be applied to amonitor for remote control and monitoring.

Here, the present invention can be variously modified as long asmodifications do not deviate from the spirit of the invention and, as amatter of course, the present invention covers these modifications.

INDUSTRIAL APPLICABILITY

The present invention is used for making video (image) stereoscopic inthe field of transmission and reception of images using televisionbroadcasting and communication lines and other fields, by utilizing thesame video data even with different models of displaying apparatus.

The invention claimed is:
 1. A stereoscopic video imaging displaysystem, wherein one reference window, which is a virtual field-of-viewframe, is set in a field of view of a stereoscopic video imagingapparatus in which imaging units each formed of a shooting lens and animage pickup device are placed on left and right in parallel to eachother; in a state in which the reference window is projected in areduced manner by the left and right shooting lenses to form an image oneach of the left and right image pickup devices, the left and rightimage pickup devices are placed in accordance with a width of each ofleft and right projected images of the reference window or image dataequivalent to the width of the projected image of the reference windowis read as standard stereoscopic video data; on an apparatus on adisplay side, left and right videos are displayed on a referencedimension display screen approximately equivalent to the referencewindow at the time of shooting the standard stereoscopic video data,with different polarizations simultaneously or in a time-divisionmanner, or the left and right videos are displayed with polarizations ina same direction in a time-division manner; polarizing eyeglasses orliquid-crystal shutter eyeglasses for separate viewing of left and rightfields of view according to a display scheme or a liquid-crystal plateis mounted immediately before each of left and right polarizing platesidentical to each other; and the liquid-crystal plates are alternatelydriven for separate viewing, and wherein a video for left is displayedat an inner position which contacts with a line connecting both ends ofthe reference dimension display screen and a left eye of an observer,and a video for right is displayed at an inner position which contactswith a line connecting both ends of the reference dimension displayscreen and a right eye of an observer, the left and right distancebetween infinity images is displayed at between 58 and 72 mm which is aninterpupillary distance of a human, so, the left and right stereoscopicimages can be seen in the same size as the reference dimension displayscreen.
 2. The stereoscopic video imaging display system according toclaim 1, wherein digital TV broadcasting waves are used as dataconveying means from the stereoscopic video imaging apparatus thatobtains the standard stereoscopic video data to a stereoscopic videodisplaying apparatus.
 3. The stereoscopic video imaging display systemaccording to claim 1, wherein a communication line is used as dataconveying means from the stereoscopic video imaging apparatus thatobtains the standard stereoscopic video data to a stereoscopic videodisplaying apparatus.
 4. A stereoscopic video imaging display systemcomprising: a stereoscopic video imaging apparatus having left and rightimaging units, the left imaging unit comprising a left shooting lens anda left image pickup device, the right imaging unit comprising a rightshooting lens and a right image pickup device, the left and rightimaging units placed parallel to each other with an angle of view andpositioned to project a reference window of a virtual field of viewframe in a reduced manner to form an image on each of the left and rightimage pickup devices, each of the left and right image pickup elementshaving a pickup element width; wherein the left and right image pickupdevices are placed in accordance with a width of each of left and rightprojected images of the reference window is read as standardstereoscopic video data; and a reference dimension display screen havinga display screen width and left and right screens exactly matching eachother and having a position and size for reproducing the referencewindow coupled to said stereoscopic video imaging apparatus, saidreference dimension display screen receiving the standard stereoscopicvideo data and displaying the reference window at the time of shootingthe standard stereoscopic video data on each of the left and rightscreens with a display magnifying power equal to a ratio between thedisplay screen width and the pickup element width, whereby thestereoscopic video imaging display system reproduces a state ofstereoscopy with high fidelity and shot data is capable of beingcommonly shared as standard stereoscopic data irrespective of a type andsize of the reference dimension display screen.
 5. A stereoscopic videoimaging display system for displaying stereoscopic images on differentdisplays without adjustment comprising: a stereoscopic video imagingapparatus having left and right imaging units, the left imaging unitcomprising a left shooting lens and a left image pickup device, theright imaging unit comprising a right shooting lens and a right imagepickup device, the left and right imaging units placed parallel to eachother with an angle of view and positioned to project a virtual field ofview frame in a reduced manner to form an image of the virtual field ofview frame on each of the left and right image pickup devices; whereinthe left and right image pickup devices are placed in accordance with awidth of each of left and right projected images of the virtual field ofview frame, the images of the virtual field of view frame on the leftand right image pickup devices are read and form standard stereoscopicvideo data; a stereoscopic video display screen comprising left andright screens exactly matching each other and having a position and sizefor reproducing and displaying the virtual field of view frame in fullsize and equivalent to the virtual field of view frame at the time ofshooting the standard stereoscopic video data; and data conveying means,coupled to said stereoscopic video imaging apparatus and saidstereoscopic video display screen, for transmitting the standardstereoscopic video data from said stereoscopic video imaging apparatusto said stereoscopic video display screen, whereby the stereoscopicvideo imaging display system reproduces a state of stereoscopy with highfidelity and shot data is capable of being commonly shared as thestandard stereoscopic video data irrespective of a type and size of saidstereoscopic video display screen.
 6. The stereoscopic video imagingdisplay system according to claim 5, wherein digital TV broadcastingwaves are used as said data conveying means between the stereoscopicvideo imaging apparatus and said stereoscopic video displaying screen.7. The stereoscopic video imaging display system according to claim 5,wherein a communication line is used as said data conveying meansbetween the stereoscopic video imaging apparatus and said stereoscopicvideo displaying screen.